TV's most popular sitcom shows its more sentimental side tonight with an episode built around Howard's discovery of a letter from his father. Odds are you'll still receive the usual quota of funny jokes, including some built around Sheldon's inability to understand sentiment — but you can also expect to see the gang rally around their friend when he needs them. It's that willingness to allow for the occasional sweet moment, and to keep the friends connected by something other than bile and mutual bitterness, that helps make this show so superior to its slot mate, Two and a Half Men, in its current, increasingly sour configuration.

One reason Grey's remains one of TV's most popular dramas — beyond, of course, a very talented and almost insanely attractive cast — is that after all these seasons, it's still capable of surprising fans without making them feel cheated. It's easy enough to trick viewers if you're willing to violate common sense and the integrity of the characters you've created, but tricking them within those confines, as Grey's did with a double-feint that left Avery (Jesse Williams) in charge of the hospital, is a lot harder. Now we'll see the repercussions, which should be considerable.

Elementary | CBS, 10 ET/PT

Watson's move from sober companion to junior detective continues as she takes on her first solo case. As long as Sherlock is still there to advise and needle, all will most likely be well, and Elementary will continue to rank as the season's most entertaining new series.